Surgical margins following rectal cancer resection impact oncologic outcomes. We examined the relationship between margin status and race, ethnicity, region of care, and facility type. Patients undergoing resection of a stage II-III locally advanced rectal cancer (LARC) between 2004 and 2018 were identified through the National Cancer Database. Inverse probability of treatment weighting (IPTW) was performed, with margin positivity rate as the outcome of interest, and race/ethnicity and region of care as the predictors of interest. In total, 58,389 patients were included. After IPTW adjustment, non-Hispanic Black (NHB) patients were 12% (p = 0.029) more likely to have margin positivity than non-Hispanic White (NHW) patients. Patients in the northeast were 9% less likely to have margin positivity compared to those in the south. In the west, NHB patients were more likely to have positive margins than NHW patients. Care in academic/research centers was associated with lower likelihood of positive margins compared to community centers. Within academic/research centers, NHB patients were more likely to have positive margins than non-Hispanic Other patients. Our results suggest that disparity in surgical management of LARC in NHB patients exists across regions of the country and facility types. Further research aimed at identifying drivers of this disparity is warranted.

BACKGROUND: Questions have been raised as to an increased risk of local recurrence with breast-conserving surgery (BCS) post NAC highlighting the uncertainty around optimal margin width in this patient population. We examined the association between margin status and local recurrence-free survival (LRFS) in patients who underwent BCS following NAC.
METHODS: We performed a retrospective cohort study of adult female patients with stage I-III breast cancer who underwent NAC followed by BCS between 2012 and 2021 at two cancer centers. Margins were categorized as \"close\" if they were < 1 mm.
RESULTS: The full cohort included 544 patients with a median age of 53 years (interquartile range [IQR] 44-64). Pathologic complete response (pCR) was achieved in 41.2% of the overall cohort (n = 224). Of the 320 with residual disease, 29.4% (n = 94) had at least one close margin, and 10.9% (n = 35) had ≥2 close margins. Median follow-up was 55 months (IQR 32-83); 4.8% had an ipsilateral breast recurrence (n = 26). Patients with pCR had a higher 5-year LRFS than those with residual disease (98.0% vs. 91.6%, p = 0.02). There was no difference in 5-year LRFS between the margin categories (clear vs. 1 close margin vs. ≥2 close margins) in those with residual disease (92.2% vs. 88.9% vs. 92.9%) (p = 0.78).
CONCLUSIONS: In patients undergoing BCS post-NAC, those who achieved pCR had a significantly higher LRFS compared with those with residual disease at the time of surgery, but LRFS was not associated with margin width nor the number of close margins.

Achieving clear resection margins at the time of lumpectomy is essential for optimal patient outcomes. Margin status is traditionally determined by pathologic evaluation of the specimen and often is difficult or impossible for the surgeon to definitively know at the time of surgery, resulting in the need for re-operation to obtain clear surgical margins. Numerous techniques have been investigated to enhance the accuracy of intraoperative margin and are reviewed in this manuscript.

OBJECTIVE: Locoregional recurrence after resection of colon cancer is increased when primary tumor margin is positive (<1 ​mm). Data is limited regarding the risk of locoregional recurrence with close margin (<1 ​mm) of histologic factors, such as intravascular tumor, intranodal tumor, tumor deposits, or extranodal extension. We hypothesized that close margin of these factors doesn\'t affect locoregional recurrence.
METHODS: A retrospective review of all colon cancer surgical resections for adenocarcinoma from 2007 to 2020 was performed. Inclusion criteria were specimens with a negative primary tumor margin but a close margin of adverse histologic factors, defined as intravascular tumor, intranodal tumor, tumor deposits, or extranodal extension within 1 ​mm of a mesenteric or circumferential margin.
RESULTS: Among 4435 pathology reports reviewed, 45 (1 ​%) of cases met inclusion criteria. Average follow-up was 38 months. The adverse histologic factor was identified as intranodal tumor in 24 (53 ​%) cases, intravascular tumor in 8 (17.8 ​%), tumor deposits in 5 (11.1 ​%), and more than one pathologic feature in 6 (13.3 ​%). There were 9 (20 ​%) recurrences; 6 (13 ​%) had distant recurrences only, 2 (4 ​%) patients had locoregional recurrences only, and 1 (2 ​%) patient had both locoregional and distant recurrence. The adverse histologic factor in these three patients was intravascular in two and both intravascular and intranodal in one.
CONCLUSIONS: Based on our results, we do not have evidence that the presence of intravascular tumor, intranodal tumor, tumor deposits, or extranodal extension within 1 ​mm of a mesenteric or circumferential margin is associated with increased risk of locoregional recurrence.

OBJECTIVE: This study conducted a comprehensive comparative analysis of three intraoral scanners (CEREC Primescan, TRIOS, CEREC Omnicam) and a lab scanner (inEosX5) assessing their precision in simulating subgingival tooth preparations.
METHODS: Utilizing a dental simulation mannequin with a 3D-printed resin structure, 100 structures with depths ranging from 0.5 to 4.0 mm were created within a square mimicking a rectangular tank surface. Four scanner groups (A-D) and five subgroups were established. Two digitization methods, a customized parallelometer and an intraoral simulation, were applied, ensuring a standardized scanning sequence. Trueness was evaluated by comparing CAD-calculated surface areas with actual dimensions, and qualitative trueness analysis was conducted using MeshLab. Surface areas were computed using the formula SA = 2lw + 2lh + 2wh. Statistical analyses, including Pearson\'s correlation coefficient, Kolmogorov-Smirnoff and Levene\'s tests, three-way ANOVA, and paired sample t-tests, elucidated relationships and differences (a=0.05).
RESULTS: A robust correlation (r = 0.850, p < 0.001) between intraoral scanner choice and scanned area depth was found. Inverse correlations were noted for experimental methods. Three-way ANOVA demonstrated significant scanner-depth interaction (F(12,760) = 760.801, p < 0.001).
CONCLUSIONS: Emphasizing high-resolution sensors and advanced technologies, the study underscores the optimal choice for subgingival digitization, acknowledging variations among scanners.

UNASSIGNED: To evaluate for correlation between intraoperative ultrasound (IOUS)-measured tumor thickness (TT) (uTT) and histopathological TT (hTT), and to compare IOUS-assisted resection with conventional resection in patients with oral tongue cancers.
UNASSIGNED: Ovid MEDLINE (1946-2023), Embase.com (1947-2023), and Web of Science (All Databases 1900-2023).
UNASSIGNED: Inclusion criteria were the use of IOUS for the management of oral tongue cancer. Studies that did not report quantitative data were excluded. Additionally, studies that were not contributory to meta-analysis, or a narrative analysis of pooled results were excluded. Selection was carried out by 2 reviewers. A total of 2417 studies were initially identified, with 12 ultimately being included in this review, and 7 included in the meta-analysis. Data were extracted by 2 investigators and were pooled using a random-effects model.
UNASSIGNED: Our meta-analysis reveals a pooled correlation coefficient of 0.92 (95% confidence interval: 0.80-0.96) for studies comparing uTT to hTT. Studies comparing IOUS-assisted resection to conventional resection found IOUS-assisted resection yielded wider nearest margins in all studies reporting this outcome.
UNASSIGNED: IOUS reliably measures TT, similarly to that of histopathology measurement. IOUS-assisted resection, which allows the surgeon to view the deep extent of tumor invasion, may increase closest radial margin distance compared to conventional resection. IOUS-assisted resection may represent a more reliable approach to achieving clear margins than conventional resection.

UNASSIGNED: Stereotactic body radiotherapy (SBRT) is increasingly applied for pelvic lymph node recurrence. Thus far, knowledge on pelvic lymph node motion during CBCT-guided SBRT is lacking and the applied margins vary between institutions. This study evaluated pelvic lymph node motion during CBCT-guided SBRT and assessed the currently applied PTV margins of 3 and 5 mm.
UNASSIGNED: In total, 45 pelvic lymph node metastases were included. One observer delineated 45 GTVs on planning CT, 224 GTVs on pre-fraction and 216 on post-fraction CBCT. The GTV centroid coordinates were derived from all images for inter- and intrafraction motion analysis. Additionally, we assessed the influence of treatment time and lesion location on lesion motion. The expected coverage of a 3-mm and 5-mm PTV margin was assessed using the inclusiveness index for GTVs on pre- and post-fraction CBCT.
UNASSIGNED: Lymph node interfraction motion was limited to 5 mm in 96-97 % of fractions for all translational directions and intrafraction lesion motion was limited to 3 mm in 97-100 % of fractions. Para-rectal lesions (11 %) were associated with significantly larger inter- and intrafraction motion compared to other pelvic locations and treatment duration showed no correlation with lesion motion. The mean (sd) lesion inclusiveness index was 99 % (5 %) for the 5-mm PTV margin and 96 % (9 %) for the 3-mm margin.
UNASSIGNED: Pelvic lymph node motion during CBCT-guided stereotactic radiotherapy was within the widely applied PTV margin of 5 mm, providing an opportunity to reduce this margin for pelvic lymph node SBRT.

BACKGROUND: In soft tissue sarcomas, unplanned resections, or so-called Whoops procedures, do occur quite frequently, thus primarily owing to the abundant presence of benign lesions. Whether re-resection reduces local recurrence or improves overall survival remains a topic of ongoing debate. The principle objective of this study was to analyze the outcomes of patients with soft tissue sarcomas of the extremities or trunk wall after an incidental marginal resection by comparing re-resections to individuals who declined the procedure.
METHODS: A total of 185 patients who underwent unplanned resection were included. These patients were stratified into two groups: Group A (n = 156) underwent re-excision, while Group B (n = 29) was treated conservatively. Depending on the clinical scenario, radio- or chemotherapy was either administered in a neoadjuvant or an adjuvant setting. The presence of residual tumor and metastatic disease was documented. Clinical outcomes, specifically local recurrence (LR), local recurrence-free survival (LRFS) and overall survival (OS), were utilized for evaluation.
RESULTS: Group B exhibited significantly larger tumors (p < 0.0001) and a higher mean age than Group A. Among the patients in Group A, 11 (5.9%) had contaminated resection margins (R1), and residual disease (RD) was observed in 93 (59.6%) of the resected specimens. In group B, 10 patients received adjuvant radiotherapy alone, 5 received chemotherapy alone, and 13 underwent a combined approach consisting of both radio- and chemotherapy. In Group A, 8% (n = 12) of the patients developed local recurrence (LR) during the observation period. Conversely, in Group B, this amount was 14% (n = 4) (n.s.). Of the 12 LR in Group A, 10 were found in the subgroup with residual disease. Overall survival and local recurrence-free survival were not significantly different between the groups. A total of 15% (n = 24) of the patients in Group A developed metastatic disease, while 10% (n = 3) in Group B developed metastatic disease (n.s.).
CONCLUSIONS: Following the reresection of unplanned resected STS, there was no statistically significant difference observed in overall survival or LR compared to patients who did not undergo re-resection. However, within the subgroup of patients with residual disease in the re-resected specimen, the OS was compromised, and the LR rate was higher. Particularly for low-grade lesions, adopting a more conservative approach seems to be justified.

In patients with oral cancer, the risk factors for local, regional, and distant recurrence according to margin status have not been well established. We aimed to determine the risk factors for recurrence by margin status and to identify a margin cut-off point for improved survival in patients with close margins. We retrospectively reviewed adult patients treated at our centre from 2009 to 2021 for primary oral cancer. Margins were classified as positive (<1 mm), close (1 to 4.9 mm), or clear (>5 mm). Univariate and multivariate analyses were performed. A total of 326 patients (210 men) were included. The mean age was 59.1 years. Margin status was close (n = 168, 51.5%), clear (n = 83, 25.4%), or positive (n = 75, 23.0%). In the univariate analysis, positive surgical margins (HR = 7.53) had the greatest impact on distant failure. Positive surgical margins-without nodal involvement-had the greatest impact on the risk of distant failure. In the close margin group, the optimal cut-off for disease-free survival (AUC = 0.58) and overall survival (AUC = 0.63) was a deep margin > 3 mm, with survival outcomes that were comparable to the clear margin group. These finding suggest that margins < 5 mm may be sufficient in certain well-defined cases. Prospective studies are warranted to confirm these findings.

Adaptive radiotherapy is characterized by the use of a daily imaging system, such as CBCT (Cone-Beam Computed Tomography) images to re-optimize the treatment based on the daily anatomy and position of the patient. By systematically re-delineating the Clinical Target Volume (CTV) at each fraction, target delineation uncertainty features a random component instead of a pure systematic. The goal of this work is to identify the random and systematic contributions of the delineation error and compute a new relevant Planning Target Volume (PTV) safety margin. 169 radiotherapy sessions from 10 prostate cancer patients treated on the Varian ETHOS treatment system have been analyzed. Intra-patient and inter-patient delineation variabilities were computed in six directions, by considering the prostate as a rigid, non-rotating volume. By doing so, we were able to directly compare the delineations done by the physicians on daily CBCT images with the initial delineation done on the CT-sim and MRI, and sort them by direction using the polar coordinates of the points. The computed variabilities were then used to compute a PTV margin based on Van Herk margin recipe. The total margin computed with random and systematic delineation uncertainties was of 2.7, 2.4, 5.6, 4.8, 4.9 and 3.6 mm in the left, right, anterior, posterior, cranial and caudal directions, respectively. According to our results, the gain offered by the separation of the delineation uncertainty into systematic and random contributions due to the adaptive delineation process justifies a reduction of the PTV margin down to 3 to 5 mm in every direction.